Various synthetic and naturally-occurring water soluble polymers have been developed which exhibit, in aqueous solution, superior thickening and flocculating properties. These polymers are being used increasingly in a number of commercial applications such as, for example, in the clarification of aqueous solutions, in papermaking operations, in the treatment of sewage and industrial wastes, as stabilizers for drilling muds, and in the secondary recovery of petroleum by waterflooding.
Although these polymers are most often available commercially as powders or as a finely divided solid, they are most frequently utilized as aqueous solutions. This necessitates that the solid polymer material be dissolved in water. Although the various polymers are more or less soluble in water, difficulty is often experienced in preparing aqueous polymer solutions because of their slow dissolution and because the solid polymer is not readily dispersible in water. Furthermore, dispersion of solid polymers in water is hindered by their tendency to clump or remain as agglomerates on contact with water. Lumps of solid polymer immediately form by the encapsulation of undissolved solids in an outer coating of water-wet polymer which retards the penetration of additional water into the agglomerate. Although many of these lumps are eventually dissolved by continued agitation, it is frequently impractical to agitate the solution for a sufficiently long period to obtain complete dissolution.
In U.S. Pat. No. 3,624,019, a process is disclosed whereby water soluble addition polymers and gums may be rapidly dissolved or dispersed in water by first preparing a water-in-oil emulsion which contains dispersed therein finely divided particles of the water soluble vinyl addition polymer or gum, thereby producing what may be termed a polymer-containing emulsion, and then inverting the polymer-containing emulsion in water whereby the water soluble vinyl addition polymer or gum is released into the water as a solution. In this way, an aqueous solution of a polymer or gum can be obtained which is active for coagulating and settling finely suspended solids from aqueous suspensions and for numerous other commercial applications of the type previously mentioned.
It would be desirable to provide a process and apparatus wherein said activation of the polymer or gum can be carried out continuously in a very simple manner.